Patients who are incontinent, comatose or otherwise unable to control their urination are typically provided with an external collection bag, such as a urinary drainage bag or a urinary leg bag. When such a patient is fitted with an indwelling Foley catheter or an external urinary device, urine in the patient's bladder is able to drain, using gravity, into the external bag. However, if the bag is elevated above the patient's urethra, gravity causes the urine to flow back into the bladder. Once outside the body, even in a collection bag, urine is easily contaminated and may harbor bacteria. Therefore, a patient with an external bag may be particularly susceptible to repeated urinary infections.
While some external urinary bag systems purport to prevent urine backflow, they may not work as advertised. Consequently, a need remains for a urinary bag system which prevents urine from flowing back into the patient's bladder.